This invention relates to a dental clamp for use in implant restorative dentistry and, more particularly, relates to a dental clamp of this type which can be used for establishing a firm and stable grip upon implant hardware that has its superior end positioned flush with or just beneath the surface of gum tissue closely surrounding the hardware.
In certain implant restorative dentistry, an endosseus fixture in the form of a titanium pin is anchored in the jawbone of the patient by inserting this pin into a closely-fitting hole provided in the jawbone of the patient and relying upon tissue integration to develop a bond between the titanium oxide coating on the pin and the closely-surrounding host bones. In one application of this type, the pins and the hole are provided with mating threads to provide, among other things, a greater bonding area for tissue integration between the pin and the surrounding bone. In another application, an unthreaded pin is inserted into a closely surrounding unthreaded hole provided in the jawbone, and a good bond is developed between the pin and the surrounding host bone by tissue integration without assistance from mating threads.
After the above-noted tissue integration has sufficiently developed, a dental prosthesis is mounted on the fixture, being attached thereto by means comprising a screw that is threaded into an internally threaded hole in the fixture or connected structure. For properly positioning the prosthesis on the fixture, a tubular abutment of preselected length is mounted on the fixture between the fixture and the prosthesis by means that prevents the abutment from rotating with respect to the fixture. In the newer applications of this technique, the superior end of the abutment, instead of being exposed, is positioned flush with or just beneath the surface of the surrounding gingiva.
When a prosthesis is to be attached to the fixture, it is customary to clamp the abutment so that it is fixed against rotation while the above-referred-to attaching screw is being threaded into the fixture. This clamping action protects the biologic integrity of the bond between the implanted fixture and the host bone by preventing this bond from being overstressed and possibly damaged by torsional forces applied to the attaching screw.
If the abutment is located with its superior end flush with or beneath the surface of the surrounding gingiva, it is difficult to firmly clamp the abutment so as to hold it against rotation. There is no apparent readily accessible portion of the abutment that can be grasped to hold the abutment and the fixture coupled thereto against rotation.